42% missed the 5ach target for infiltration Heat loss co-efficient 75-105% worse than predicted
Stamford Brook Findings: Infiltration Lights, loft hatches, wall/floor and wall/roof junctions, partition walls Patio door – unsealed threshold Rooflights leaked around frames, seals and trickle vents Service penetrations particular problem
Stamford Brook Findings: Heat loss
Poor design AND
Not built ‘as designed’
Party wall heat losses
Stamford Brook Findings Nominal vs. Realised Heating System Efficiencies Nominal vs. Realised Thermal Bridging Y-values Nominal vs. Realised Fabric U-values ‘ Build-ability’ problems and lack of knowledge Occupant effects – e.g. Removing CFL’s
UK Construction Standards: Some Shocking Facts
50% of new builds miss ‘as designed’ energy use by up-to 50%.
30% of new builds fail infiltration standard of 10ach@5pa
Energy Saving Trust (2004)
Room in roof U-values on average 104% worse than ‘as calculated’
Average full-fill cavity wall was 20% worse than ‘as calculated’
Dept. Environment Travel Regions (DETR) (2001 report)
Energy use in residential buildings has increased by 20% since 1970
Building Research Establishment (BRE 2003+2007)
If I was to go there, would I start here? UK Construction industry 2008 UK Construction industry 2016
Eco-clichés get in the way of good, efficient and truly environmental solutions.
Solutions: Technology Problems
Overstatement of performance
Disposal / recycling
Capital expenditure choices
Excuse for envelope
There is Another Way! We have the solutions We have the knowledge We have the research We have the built case-studies Its been done before (Look over the North Sea and oop North at our neighbours...)
“ Construction is about creating thermal efficiency, not mini power stations.”
Imtiaz Farookhi Chief Executive NHBC
Eco or Sustainable or....
‘ Ultra low energy building standard.’
‘ ...based on an energy consumption target.’
‘ ...quality label for new and refurbished low-energy-consumption buildings.’
UK 2006 L2
‘ Conservation of fuel and power...’
Where are the savings?
Clear that space heating and DHW are the key areas
Lights, appliances and cooking are 'simple'
We have the solution no.1
Thermal coherence of the building shell
Good (low) U Values
Good (low) Y Values
Low Infiltration rates
We have the solution no.2
Passive solar (heat) gain
Passive solar (light) gain
Manage glazing heat loss
Shading (planting or built
We have the solution no.3
Increase in air-tightness means:
Avoid toxic or off-gassing materials
10-3ach = Passive ventilation?
3ach or better = MVHR?
We have the solution no.4
effective ventilation (MVHR or passive)
True ‘Breathing wall’ systems
We have the solution no.5
Low energy lights
Reduce dead legs and pipe runs
We have the solution no.6
Lower heating and cooling loads and peak demands
use renewables effectively
Summary of ‘The Solution’
Efficiency / passive is 80% of the battle
Renewables / active /technology are last 20%
Think about managing moisture & removing toxins
If you could focus on one thing....
“ Thermal bridging was shown as the worst area of non-compliance. Other significant non-compliance areas included conservatories, u-values , areas of windows , doors and rooflights , internal lighting , commissioning certificates , O&M manuals and air-leakage”
The Energy Efficiency Partnership for Homes (Future Energy Solutions)
Building Regulations Compliance (BRE )
The Effect of y-values
The importance of detailing: ThermoPlan
Window on ‘outside’ = psi of 0.159w/m2/k
Window ‘setback’ = psi of 0.099w/m2/k
Low Ψ values
Un-accredited + 0.15w/m 2 /k
Accredited + 0.08w/m 2 /k
ThermoPlan +0.04w/m 2 /k
Pavaclad +0.04w/m 2 /k
Diffutherm + 0.02w/m 2 /k
UK Construction: The Solution
Use systems that have proven track record in low energy buildings.
Use systems that with low Ψ / Y values and low U-values.
Ensure that U, Ψ and Y values are built ‘as designed’
Use construction systems that have an airtight strategy and a contractor responsible for airtightness.
Build it efficiently Article: Joseph Little, Deantus Projects Ltd in Construct Ireland Is this the real challenge?